Back pain is a serious and potentially debilitating condition which affects a majority of people at some point in their lives. Back pain is currently the second leading cause of absenteeism from work after the common cold and accounts for 15% of sick leaves. In the United States alone back injuries are estimated to cause 100 million lost days of work annually. The lumbar region is the primary source of pain for 85% of back pain sufferers.
Many approaches are in current use to address lumbar pain including lumbar belts of various kinds, static traction devices, heat pads, physiotherapy, drugs, surgery, and exercise regimes.
Despite the fact that people have been developing devices to alleviate back pain for hundreds of years, there remains a need for effective apparatus for relieving back pain and for relieving other anatomical structures. Such apparatus should preferably be as comfortable to wear as practical and should interfere with a wearer's activities no more than necessary.
More generally, there is also a continuing need for actuators which overcome various disadvantages of currently available actuators in other fields. Actuators are used in a great many fields including industrial controls, automated equipment, undersea equipment, heavy lifting, medical catheters, etc. A wide range of actuators are available. Cylinders are the most common type for both pneumatic and hydraulic applications. Other actuator types include rolling diaphragms, and bellows. As previously stated, there are a wide variety of actuators which are available commercially.
It is desirable to provide actuators which are suitable for their intended applications and can be manufactured in a manner which is cost effective for the desired application.